From patchwork Mon Nov 18 18:15:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 11250091 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 14ED1109A for ; Mon, 18 Nov 2019 18:16:08 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E79FB222A4 for ; Mon, 18 Nov 2019 18:16:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="IGLowM4p"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="HA8Rydxc" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E79FB222A4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=bPyB1BcXN1t2NnHqm5q+Iy2RyW/RE7qDYBd3oUrNoPU=; b=IGLowM4p5cA+zx oifaSH6vCVZlL5K5dgB2hbA0FVoY++O1HrKkceMY7sYeOURgqr9Wo6PoXEs764OG2z2IROw5m32Tk I0VpQVlBl3YugzwjgjJbJyBTvhN3t9WZQ5IoFOWHcdLbRJYkDiCFGr3qqmr8lZV6t84mYc2aN0MBA YU/SBorkD/f9Xf+YS8ip0JGW7gpUZBr4T+xOCR0C9A8Wd9Xm8ddSmYcNSUTKxS3W+58MMN1UF926s 4+TSiv2o9VZpwggKPMAaNNIs9M2iyta1UdZ0ZJURng/u/jWlwB/w2IoRY7A+RKCwxDtS6LOvlfqF9 XWEIhu/Vbfg3M1kiiQiQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iWlZC-0005Zq-D4; Mon, 18 Nov 2019 18:16:02 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iWlZ1-0005JX-Rc for linux-arm-kernel@lists.infradead.org; Mon, 18 Nov 2019 18:15:53 +0000 Received: from localhost.localdomain (lfbn-mar-1-550-151.w90-118.abo.wanadoo.fr [90.118.131.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D7F3A222A4; Mon, 18 Nov 2019 18:15:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574100951; bh=Kxw4VlsuOkmZEobv5swVsOUhtNw58aXqSY6TvZ8HM8Q=; h=From:To:Cc:Subject:Date:From; b=HA8Rydxc28A0PyBDzaoN4cC1ZuEKiCy6E72UY81gWVnwFAnfxLj7sW9UaQnSkIo6Q fhKjesm2v3FTbYNaJxTsIgE7At4jg628VPrGDLfbkfptJd9ekKWdcG8j/tlgHgfnVG eiKabSTveily+5xZQNL1AlQadtGUdxky7kQoWewo= From: Ard Biesheuvel To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 0/2] ARM/decompressor: deal with disabled CP15 barrier instructions Date: Mon, 18 Nov 2019 19:15:41 +0100 Message-Id: <20191118181543.122968-1-ardb@kernel.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191118_101551_947545_CA1F86D7 X-CRM114-Status: GOOD ( 12.02 ) X-Spam-Score: -5.2 (-----) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (-5.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at https://www.dnswl.org/, high trust [198.145.29.99 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.0 DKIMWL_WL_HIGH DKIMwl.org - Whitelisted High sender X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: maz@kernel.org, rmk+kernel@armlinux.org.uk, linus.walleij@linaro.org, Ard Biesheuvel Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org From: Ard Biesheuvel While trying to test my v4.4 backport of the firmware/hypervisor based spectre v1/v2 mitigations for 32-bit ARM, I noticed that KVM/qemu failed to boot my kernel while it booted fine under TCG emulation. As it turns out, KVM/qemu may instantiate the VCPU with support for CP15 barrier instructions disabled, causing them to UNDEF and crash the decompressor. I already fixed the same issue for UEFI boot, but since v4.4 does not support that, I only noticed now that this is an issue for bare metal as well. Changes since v1: - instead of using v7 barriers in the v7 code, enable the CP15 barriers - this way, we can keep using the v7 routines for some v6 CPUs that implement CPUID instructions (causing them to take the v7 path) but not for the v7 barriers. - applied Marc's and Linus's acks to #2 only I have tested this via kernelci [0], which includes the v6 pogoplug that got broken by the v1 version of this series. [0] https://kernelci.org/build/ardb/branch/for-kernelci/kernel/v5.4-rc8-2-gcaea8d2861c8/ Cc: Russell King Cc: Linus Walleij Cc: Marc Zyngier Ard Biesheuvel (2): ARM/decompressor: enable CP15 barrier instructions in v7 cache setup code Revert "ARM: 8857/1: efi: enable CP15 DMB instructions before cleaning the cache" arch/arm/boot/compressed/head.S | 29 ++++++++++---------- 1 file changed, 14 insertions(+), 15 deletions(-)